High-intensity Interval Exercise Protocol Research Articles

High Intensity Interval Exercise Causes Acute Microvascular Dysfunction in Elderly Individuals with Low Cardiorespiratory Fitness - A Pilot Study

Background: Frailty is strongly associated with low physical and cardiorespiratory fitness, and unfortunately is observed in 20-50% of the ~50 million adults that experience surgical stress in the U.S. each year. The peripheral microvasculature may serve as a potential target to increase resilience to stress and improve postoperative outcomes. A better understanding of how the microvasculature responds to stress in elderly individuals with low fitness is thus needed. Objective: To define the relationship between cardiorespiratory fitness and microvascular resiliency to stress in elderly individuals. Hypothesis: Elderly individuals with low cardiorespiratory fitness will show acute reductions in acetylcholine (Ach)-mediated dilation of the skin microvasculature following the physiological stressful stimulus of high intensity interval exercise (HIIE). Methods: This was a prospective, observational study that enrolled elderly individuals aged 65-85 years from the community. Each participant was asked to complete two study visits. During visit 1, participants completed the Frailty Index and performed a graded cardiopulmonary exercise test (CPET) on a cycle ergometer with a metabolic cart to measure peak total body oxygen consumption (VO2 Peak). During visit 2, laser Doppler flowmetry with dermal microdialysis was performed on the ventral forearm to measure peak cutaneous microvascular vasodilation to Ach (10 mM). After baseline assessment, the participants performed a HIIE protocol where they repetitively switched between exercising at 70% of the peak workload achieved during the CPET for 60 seconds, followed by a 60 second active recovery at 10 watts. These intervals were repeated 12 times, for a total exercise duration of 24 min. Thirty minutes following exercise, Ach-mediated dilation of the cutaneous microvasculature was reassessed. Maximum dilator capacity of each site was assessed by infusing sodium nitroprusside (28 mM) and heating the skin to 43 °C. Results: Six individuals (1 male, 5 females; mean age 68 ±4 years) completed all study procedures. Based on age- and sex-predicted normative values for VO2 Max, three of the individuals had high physical fitness while three had low fitness (mean VO2 Peak = 27.5±1.1 vs. 13.6±3.4 ml/kg/min, respectively). Prior to HIIE there was no difference in peak dilation to Ach between the individuals with high vs. low fitness (% max dilation = 72±13 vs. 83±13, respectively). During HIIE, the individuals reached a Borg rating of perceived exertion of 15±4 (out of 20) and their peak heart rate was 74±15% of their age-predicted maximum. Ach-mediated dilation of the dermal microvasculature was reduced following HIIE in elderly individuals with low cardiorespiratory fitness (pre vs. post % maximum dilation = 82±13 vs. 49±27, respectively; mean change = -34±40 %) but unchanged in those with high fitness (pre vs. post % maximum dilation = 72±13 vs. 78±10, respectively; mean change = 5±3 %). Using Pearson correlation tests there was a strong correlation between the change in peak Ach-mediated dilation pre vs. post HIIE and both VO2 Peak (r=0.82, p=0.04) and Frailty Index score (r=-0.98, p<0.001). Conclusion: Microvascular resilience to acute stress is decreased in elderly individuals with low cardiorespiratory fitness compared to those with high fitness. None. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Acute effect of moderate and high-intensity interval exercises on asprosin and BDNF levels in inactive normal weight and obese individuals

This study aimed to examine the acute effects of moderate-intensity aerobic and high-intensity interval exercise protocols on Asprosin and Brain-Derived Neurotrophic Factor (BDNF) levels in inactive normal weight and obese individuals. A total of 20 male individuals aged 18–65 years, ten normal weight (NW) (Body Mass Index (BMI): 18.5–24.99 kg/m2) and 10 obese (Ob) (BMI: 24.99–35.00 kg/m2) participated in this study, voluntarily. Moderate aerobic exercise (AE) (main circuit 30 min, between 40 and 59% of Heart Rate Reserve: HRR) and High-Intensity Interval exercise (HIIE) running protocols (main circuit 20 min, between 75 and 90% of the HRR for 1 min*10 times, and 1-min active rest at 30% of the HRR) was applied to the volunteer participants in the morning hours (08.00–10.00 a.m.), following the night fasting (at least 8–10 h) for at least 3 days between each other. Blood samples were collected from the participants before and immediately after each exercise protocol, and serum asprosin and BDNF hormone levels were determined by Enzyme-Linked Immunosorbent Assay” method. Basal serum asprosin was found to be significantly higher in the Ob group compared to the NW group (p < .001), while the basal serum BDNF hormone was found to be lower (p < 0.05). It was observed that the serum asprosin level of both groups decreased significantly after both AE and HIIE protocols (p < 0.05). In addition, there was a significantly higher decrease in serum asprosin level in the Ob group compared to the NW group after HIIE protocol. For the Ob group, serum BDNF level increased considerably after HIIE protocol compared to AE protocol (p < 0.05). Serum asprosin was found to be higher in the Ob group, while the serum BDNF was found to be lower. In addition, the acute exercises of different intensity significantly affected hormones that regulate appetite metabolism. In particular, it was observed that the HIIE protocol had a greater effect on the regulation of appetite (hunger-satiety) in the Ob group. This result can be taken into account when planning training programs for these individuals.

Acute physiological responses to high-intensity interval exercise in patients with coronary artery disease.

Time spent closer to maximal effort during exercise is a potent stimulus for cardiorespiratory adaptations. The primary purpose was to determine which high-intensity interval exercise (HIIE) protocol provided the greatest physiological stimulus by comparing time spent ≥ 90% peak oxygen consumption (V̇O2peak) and heart rate reserve (HRR) in patients with coronary artery disease (CAD) in response to 3 HIIE protocols and the exercise standard of care, moderate-intensity continuous exercise (MICE). A secondary purpose was to assess protocol preference. Fifteen patients with CAD (6 females, 67 ± 6years) underwent measurements of V̇O2 and heart rate during MICE and three HIIE protocols all performed on a treadmill. The HIIE protocols included one with long intervals (4 × 4-min), short intervals (10 × 1-min), and an adapted version of the 4 × 4 [Toronto Rehabilitation Institute Protocol, (TRIP)]. Time spent ≥ 90% V̇O2peak and HRR were compared. Time spent ≥ 90% V̇O2peak was higher during 4 × 4 (6.3 ± 8.4min) vs. MICE (1.7 ± 3.9min; P = 0.001), while time spent ≥ 90% HRR was higher during 4 × 4 (6.0 ± 5.3min) vs. MICE (0.1 ± 0.2min; P < 0.001) and 10 × 1 (0.7 ± 0.8min; P = 0.016). TRIP had similar responses as 10 × 1 and MICE. The 10 × 1 was the most preferred protocol and the 4 × 4 was the least preferred protocol. Longer intervals (4 × 4) provided the greatest physiological stimulus compared to the exercise standard of care and shorter intervals. However, this protocol was least preferred which may impact exercise adherence. Although the physiological stimulus is important to maximize training adaptations, exercise preferences and attitudes should be considered.

Higher Oxygen Uptake And Heart Rate Response In Recovery From Acute High Intensity Interval Exercise

Optimizing energy expenditure is paramount to achieving negative energy balance and promoting weight loss. High intensity interval exercise (HIIE) has been popularized for its ability to reduce body fat despite its time efficiency, yet it is unknown if the majority of calories burned during acute HIIE stems from completion of each interval or subsequent recovery period. Moreover, it is thought that the adaptive response to HIIE is mediated by the acute metabolic stress, but it is unknown if this stems from the interval or recovery phase of training. PURPOSE: To compare oxygen uptake (VO2) and heart values (HR) acquired during HIIE and in subsequent recovery to various HIIE regimens. METHODS: Data from 6 previously-published studies requiring various cycling-based HIIE regimens were analyzed from 89 healthy and active men and women (age, BMI, PPO, and VO2max = 25 ± 6 yr, 24 ± 3 kg/m2, 276 ± 59 W, and 40 ± 7 mL/kg/min). HIIE protocols included six to twelve 30 s - 2.5 min efforts at intensities ranging from 70 - 85 %PPO, with recovery periods ranging from 30 - 75 s. During exercise, VO2, HR, and blood lactate concentration (BLa) were acquired. RESULTS: HIIE bouts elicited peak HR, VO2, and BLa equal to 90 ± 6 %HRmax, 76 ± 12 %VO2max, and 10 ± 4 mM, respectively, and calorie expenditure was equal to 173 ± 47 kcal. Paired t-test revealed significantly higher VO2 (1.95 ± 0.46 L/min vs. 2.02 ± 0.46 L/min, p < 0.001) and HR (158 ± 14 b/min vs. 161 ± 15 b/min, p < 0.001) during recovery from acute HIIE versus the intervals. Significant inverse associations were demonstrated between VO2max and peak VO2 (r = -0.40, p < 0.001) and peak HR (r = -0.30, p = 0.004) attained during HIIE. CONCLUSIONS: Data reveal a significantly higher VO2 during recovery from HIIE compared to each interval, which may be due to slow O2 kinetics of these average fitness adults. HR was also higher in recovery suggesting a severe stress on the cardiovascular system not only during each interval, but also in recovery despite the low power outputs completed. More fit participants showed a blunted VO2 and HR response to HIIE suggesting that they may be at lower relative intensities versus less fit individuals. The structure of recovery periods as well as the interval efforts may be modified by clinicians to optimize calorie expenditure and metabolic stress of acute HIIE.

Interleukin-6, undercarboxylated osteocalcin, and brain-derived neurotrophic factor responses to single and repeated sessions of high-intensity interval exercise

ObjectivesThe purpose of this study was to compare the effects of a single session of high-intensity interval exercise (HIIE) with 2 consecutive HIIEs, separated by 3 h of recovery, on plasma interleukin-6 (IL-6), undercarboxylated osteocalcin (ucOC), and brain-derived neurotrophic factor (BDNF) responses. MethodsTwenty male recreational endurance athletes completed two HIIE trials in a randomized crossover design: a single session of HIIE on the single exercise day (HIIE-S) and two sessions of HIIE 3 h apart on the double exercise day (HIIE-D). The HIIE protocol consisted of 10 × 1 min cycling at 100 % of peak oxygen uptake, with 75 s of low-intensity cycling at 60 W. Blood samples were collected to analyze IL-6, ucOC, and BDNF levels before and immediately after HIIE on the HIIE-S and before and immediately after the second HIIE on the HIIE-D. ResultsBoth HIIE interventions significantly increased (p < 0.001) plasma IL-6 (HIIE-S 33.90 % vs HIIE-D 31.04 %; p = 0.64), ucOC (HIIE-S 37.18 % vs HIIE-D 39.54 %; p = 0.85), and BDNF levels (HIIE-S 236.01 % vs HIIE-D 216.68 %; p = 0.69), with no group effect. ConclusionsOur results demonstrate that performing two consecutive HIIEs on the same day with a 3-h rest results in similar changes in plasma levels of IL-6, BDNF, and ucOC compared with a single session of HIIE.

Royal Jelly Plus Coenzyme Q10 Supplementation Enhances High-Intensity Interval Exercise Performance via Alterations in Cardiac Autonomic Regulation and Blood Lactate Concentration in Runners.

PurposeThis study aimed to examine whether oral royal jelly (RJ) and coenzyme Q10 (CoQ10) co-supplementation could improve high-intensity interval exercise (HIIE) performance in runners, reducing exercise-induced lactic acidosis and decreasing elevated sympathetic tone following exercise.MethodsThirty regional-level runners (age: 19 ± 1 years; height: 173 ± 2 cm; body mass: 68.9 ± 2 kg; body mass index: 23.1 ± 1 kg/m2) were randomly allocated to receive either 400 mg of RJ and 60 mg of CoQ10 (RJQ) or matching placebo (PLA) once daily for 10 days. Exercise performance expressed as time taken to complete HIIE was evaluated at baseline, and then reassessed at day 10 of intervention. HIIE protocol applied to the runners included three repetitions of 100 m distance at maximum possible speed interspersed with 45 s of recovery periods. Indices of heart rate variability and blood lactate concentration were also measured before and immediately after HIIE in each group.ResultsHIIE performance significantly improved in RJQ group (p = 0.005) compared to PLA group. Blood lactate levels and sympathetic influence on the heart were significantly lower both before and after the HIIE in athletes who received RJQ (p < 0.05) compared to PLA. Regression analysis showed that oral RJQ administration for 10 days was significantly associated with reductions in HIIE-induced increases in blood lactate concentration and enhanced cardiac parasympathetic modulation following exercise compared to PLA. Principal component analysis revealed that runners treated with RJQ are grouped by the first two principal components into a separate cluster compared to PLA. Correlation analysis demonstrated that the improvements in runners’ HIIE performance were due in significant part to RJQ-induced reduction of increment in blood lactate levels in response to exercise in combination with a more rapid shift in autonomic activity toward increased parasympathetic control early at post-exercise.ConclusionThese findings suggest that RJQ supplementation for 10 days is potentially effective for enhancing HIIE performance and alleviating adverse effects of increased intramuscular acidity and prolonged sympathetic dominance following intense exercise.

Royal jelly plus coenzyme Q10 supplementation improves high-intensity interval exercise performance via changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in swimmers: a randomized, double-blind, placebo-controlled pilot trial.

ABSTRACTBackgroundExcessive production of free radicals caused by many types of exercise results in oxidative stress, which leads to muscle damage, fatigue, and impaired performance. Supplementation with royal jelly (RJ) or coenzyme Q10 (CoQ10) has been shown to attenuate exercise-induced oxidant stress in damaged muscle and improve various aspects of exercise performance in many but not all studies. Nevertheless, the effects of treatments based on RJ plus CoQ10 supplementation, which may be potentially beneficial for reducing oxidative stress and enhancing athletic performance, remain unexplored. This study aimed to examine whether oral RJ and CoQ10 co-supplementation could improve high-intensity interval exercise (HIIE) performance in swimmers, inhibiting exercise-induced oxidative stress and muscle damage.MethodsTwenty high-level swimmers were randomly allocated to receive either 400 mg of RJ and 60 mg of CoQ10 (RJQ) or matching placebo (PLA) once daily for 10 days. Exercise performance was evaluated at baseline, and then reassessed at day 10 of intervention, using a HIIE protocol. Diene conjugates (DC), Schiff bases (SB), and creatine kinase (CK) were also measured in blood plasma and saliva before and immediately after HIIE in both groups.ResultsHIIE performance expressed as number of points according to a single assessment system developed and approved by the International Swimming Federation (FINA points) significantly improved in RJQ group (p = 0.013) compared to PLA group. Exercise-induced increase in DC, SB, and CK levels in plasma and saliva significantly diminished only in RJQ group (p < 0.05). Regression analysis showed that oral RJQ administration for 10 days was significantly associated with reductions in HIIE-induced increases in plasmatic and salivary DC, SB, and CK levels compared to PLA. Principal component analysis revealed that swimmers treated with RJQ are grouped by both plasmatic and salivary principal components (PC) into a separate cluster compared to PLA. Strong negative correlation between the number of FINA points and plasmatic and salivary PC1 values was observed in both intervention groups.ConclusionThe improvements in swimmers’ HIIE performance were due in significant part to RJQ-induced reducing in lipid peroxidation and muscle damage in response to exercise. These findings suggest that RJQ supplementation for 10 days is potentially effective for enhancing HIIE performance and alleviating oxidant stress.AbbreviationsRJ, royal jelly; CoQ10, coenzyme Q10; HIIE, high-intensity interval exercise; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase; RJQ, royal jelly plus coenzyme Q10; PLA, placebo; FINA points, points according to a single assessment system developed and approved by the International Swimming Federation; ROS, reactive oxygen species; 10H2DA, 10-hydroxy-2-decenoic acid; AMPK, 5′-AMP-activated protein kinase; FoxO3, forkhead box O3; MnSOD, manganese-superoxide dismutase; CAT, catalase; E, optical densities; PCA, principal component analysis; PC, principal component; MCFAs, medium-chain fatty acids; CaMKKβ, Ca2+/calmodulin-dependent protein kinase β; TBARS, thiobarbituric acid reactive substances; MDA, malondialdehyde.

Effect of high-intensity interval exercise on renal artery hemodynamics in healthy young adults.

High-intensity interval exercise is useful for sustained exercise; however, its effect on renal artery hemodynamics is unclear. This study aimed to evaluate changes in renal artery blood flow velocity due to high-intensity interval exercise. Ten healthy adults (age, 23.5±1.2 years) completed high-intensity interval exercise and moderate-intensity continuous exercise protocols on separate days. The high-intensity interval exercise protocol (total duration, 26 min) comprised eight sets of high-intensity exercise sessions at 85% maximum oxygen uptake for 1 min, with intervals of 40% maximum oxygen uptake for 2 min between sets. The moderate-intensity continuous exercise protocol comprised 40 min of exercise at 40% maximum oxygen uptake. Renal artery blood flow velocity and natural log-transformed high frequency spectral power (an index of cardiac parasympathetic nervous system activity) were measured before and after exercise. Additionally, exercise enjoyment was measured using a questionnaire. Renal artery blood flow velocity did not significantly differ between protocols or timepoints for either protocol. However, the natural log-transformed high frequency spectral power was significantly lower with high-intensity interval exercise than with moderate-intensity continuous exercise (P<0.001, F=25.97) during exercise and at 10 min after exercise, and it did not return to pre-exercise levels with high-intensity interval exercise. Moreover, there was no significant difference in exercise enjoyment between the two protocols. In healthy young adults, high-intensity interval exercise reduces parasympathetic activity; however, it does not produce any significant changes in renal artery hemodynamics after exercise.

Melatonin reduces muscle damage, inflammation and oxidative stress induced by exhaustive exercise in people with overweight/obesity.

Intense physical exercise leads to inflammation, oxidative stress and muscle damage, and these responses are of greater magnitude in people with obesity. Melatonin (MLT) is considered an endogenous antioxidant which may have beneficial effects against inflammation, oxidative stress and promote tissue repair after exercise. The aim of this study was to examine the effect of MLT on inflammatory parameters, oxidative stress and muscle damage in people with overweight/obesity after a high-intensity interval exercise (HIIE). A total of 23 subjects with obesity (9 men and 14 women) age: 33.26 ± 9.81 years, BMI: 37.75 ± 8.87 kg.m-2 were randomized to participate in two experimental sessions: HIIE + Placebo and HIIE + MLT (3 mg). The HIIE protocol corresponds to 8 intervals of 1 min (90% of the maximal aerobic power (MAP)) alternating with 2 min recovery (45% of the MAP). Blood samples were drawn before and 5 min after each exercise session. MLT ingestion attenuated the increase of inflammation (C-reactive protein, white blood cells (P < 0.001, ηp2 = 0.45; for both) and Neutrophils (P < 0.01, ηp2 = 0.36)) and hepatic and muscle damage (Aspartate aminotransferase (P < 0.01, ηp2 = 0.25), Alanine aminotransferase (P < 0.01, ηp2 = 0.27) and Creatine kinase (P = 0.02, ηp2 = 0.23). MLT also attenuated the exercise induced lipid and protein peroxidation (i.e., Malondialdehyde (P = 0.03, ηp2 = 0.19) and AOPP (P < 0.001, ηp2 = 0.55)). Concerning the antioxidant status, MLT intake increased Thiol (P < 0.01, ηp2 = 0.26) and Catalase (P < 0.01, ηp2 = 0.32) and decreased Uric acid (P = 0.02, ηp2 = 0.2) and Total bilirubin (P < 0.01, ηp2 = 0.33). MLT intake before HIIE reduced muscle damage by modulating oxidative stress and preventing overexpression of the pro-inflammatory mediators in people with obesity.

HIIE Protocols Promote Better Acute Effects on Blood Glucose and Pressure Control in People with Type 2 Diabetes than Continuous Exercise.

This study compared the acute effects of a session of different high-intensity interval exercise (HIIE) protocols and a session of moderate-intensity continuous exercise (MICE) on blood glucose, blood pressure (BP), and heart rate (HR) in people with Type 2 Diabetes Mellitus (DM2). The trial included 44 participants (age: 55.91 ± 1.25 years; BMI: 28.95 ± 0.67 kg/m2; Hb1Ac: 9.1 ± 2.3%; 76 mmol/mol) randomized into three exercise protocols based on the velocity at which maximum oxygen consumption was obtained (vVO2 max): long HIIE (2 min at 100% vV̇o2peak + 2 min of passive rest); short HIIE (30 s at 100% vV̇o2peak + 30 s of passive rest); or MICE (14 min at 70% vV̇o2peak) on a treadmill. Capillary blood glucose, BP, and HR measurements were taken at rest, during peak exercise, immediately after the end of exercise, and 10 min after exercise. Long and short HIIE protocols reduced capillary blood glucose by 32.14 mg/dL and 31.40 mg/dL, respectively, and reduced systolic BP by 12.43 mmHg and 8.73 mmHg, respectively. No significant changes were observed for MICE. HIIE was found to promote more acute effects than MICE on glycemia and BP in people with DM2.

Acute Physiological Responses to Moderate-Intensity Continuous, High-Intensity Interval, and Variable-Intensity Intermittent Exercise

ABSTRACT Purpose: This study examined acute physiological responses to moderate-intensity continuous exercise (MICE), variable-intensity intermittent exercise (VIIE), and high-intensity interval exercise (HIIE) protocol, matched for total work output in healthy adults (n = 8, age = 25.1 ± 6.0 yrs). Methods: Three experimental trials were completed in a random order. MICE was continuous exercise at 40% of peak work rate (WRpeak). VIIE consisted of sixteen 10-sec bursts at 120% WRpeak, sixteen 20-sec bursts at 60% WRpeak and recovery at 20% WRpeak interspersed throughout the protocol. HIIE consisted of eight intervals of 2 minutes at 70% WRpeak and 1 minute at 20% WRpeak. Oxygen consumption during work-intervals and time within moderate and vigorous-intensity zones determined the magnitude and duration of physiological stresses. Perceptual responses were measured by affective response and post-exercise enjoyment (PACES). Repeated-measure ANOVAs analyzed differences between trials. Statistical significance was established if p ≤ 0.05. Results: Oxygen consumption during work-intervals in VIIE was greater than MICE, but less than HIIE. VIIE and HIIE had similar duration within vigorous-intensity zone (11.1 ± 3.5 min vs. 13.5 ± 1.3 min); both were greater than MICE (4.9 ± 1.1 min). The time spent in the moderate-intensity zone was different between all trials (VIIE = 11.1 ± 2.0 min; MICE = 17.4 ± 5.2 min; HIIE = 4.9 ± 0.4 min). Affective responses were similar among all trials. Post-exercise enjoyment was greater in VIIE than HIIE; both were not different from MICE. Conclusion: These results suggests the VIIE paradigm could be a viable alternative to HIIE and MICE protocols.

Response of coagulation factors to different high intensity interval exercise protocols in young overweight men

هدف: هدف تحقیق حاضر بررسی پاسخ فاکتورهای انعقادی به پروتکل های مختلف فعالیت تناوبی در مردان دارای اضافه وزن بود.مواد و روش ها: تعداد 10مرد جوان ( شاخص توده بدنی 4/1±5/26 کیلوگرم/متر2) به عنوان آزمونی انتخاب شدند. بعد از تعیین حداکثر توان، آزمودنی ها در دو جلسه با فاصله یک هفته، پروتکل­ تناوبی با شدت 110% حداکثر توان ، 6 تکرار 30 ثانیه ای با استراحت های فعال 5/3 دقیقه ای و پروتکل تناوبی با شدت 85% حداکثر توان به صورت 6 تکرار 2 دقیقه ای با استراحت های فعال 2 دقیقه ای را اجرا کردند. قبل و بلافاصله بعد از هر پروتکل اندازه گیری­ها به عمل آمد. جهت بررسی آماری از آزمون تی مستقل و در سطح 05/0≥ P استفاده شد.یافته ها: نتایج تحقیق نشان داد یک جلسه فعالیت تناوبی با شدت بالا صرف نظر از نوع پروتکل تاثیر معنی داری بر مقادیر زمان پروترومبین نداشت (05/0P> )، اما بین پاسخ زمان پروترومبین به دو پروتکل تفاوت معنی داری را نشان داد (05/0p <). یک جلسه فعالیت تناوبی با شدت بالا تاثیر معنی داری در متغیرهای زمان نسبی ترومبوپلاستین و فیبرینوژن نداشت (05/0P>)، بررسی تفاوت پاسخ این متغیرها به دو پروتکل نیز تفاوت معنی داری را نشان نداد (05/0P>).نتیجه گیری: هر چند شدت بالای فعالیت باعث افزایش نسبی فاکتورهای انعقادی و کاهش زمان انعقاد شد ولی نوع پروتکل بر این تغییرات موثر نبود؛ احتمالا این پروتکل­ها با تغییرات اندک در فیبرینوژن به عنوان یکی از پروتئین های التهابی مرحله حاد، می توانند به عنوان شیوه تمرینی مفیدی برای افراد غیرفعال در نظر گرفته شوند.

Effects of high-intensity interval exercise and moderate-intensity continuous exercise on executive function of healthy young males

PurposeThis study compared the executive function (EF) performance induced by moderate-intensity continuous exercise (MICE) versus high-intensity interval exercise (HIIE), under two exercise modalities (i.e., running vs. cycling), and explored whether the changes in EF performance were related to the hemodynamics response of the cerebral prefrontal area of the brain. MethodsIn a randomized cross-over design, 16 male participants completed 4 main trials, i.e., 40 min of moderate-intensity continuous running (MICR) or cycling (MICC) with 60% maximal oxygen consumption (VO2max), 33 min of high-intensity interval running (HIIR) or cycling (HIIC). For HIIR or HIIC trials, the exercise intensity was 60% VO2max for the first 5 min, followed by four 4-minute bouts of exercise at 90% VO2max, separated by 3-minute active recovery at 60% VO2max. EF was assessed via the Eriksen Flanker task (EFT) before (Pre), immediately after (Post 0), and 10 min after exercise (Post 10). Functional near-infrared spectroscopy (fNIRS) measured oxygenated hemoglobin (O2Hb) and deoxygenated hemoglobin (HHb) concentrations in the prefrontal area. Each main trial measured the concentrations of blood glucose and lactate, heart rate, and rate of perceived exertion. Results(1) Compared to the reaction time in EFT during the pretest, the corresponding reaction time was shorter at Post 10 (P < 0.01) but not at Post 0 (P = 0.06). Specifically, reaction time was shorter at Post 10 than in the pretest in HIIC (P = 0.04), MICC (P = 0.01), and HIIR (P < 0.01) but not MICR. (2) The fNIRS results revealed that O2Hb concentrations in the left dorsolateral prefrontal cortex area were much lower during Post 10 than during the pretest. (3) The blood lactate concentrations were not associated with EF performance regarding both accuracy and reaction time. ConclusionCompared to the pretest, EF was greater after the 10-minute rest during recovery but not immediately after exercise. The different HIIE or MICE protocols adopted in the present study may elicit minor differences regarding their effects on EF.

Might High-Intensity Interval Exercise Be Remembered as More Pleasurable? An Attempt to Test the Peak-End Rule in the Exercise Context

Given humans' limited ability to recall past experiences for evaluation, scholars have proposed the peak-end rule stating that if perceived discomfort at the end of an aversive experience is lower than the peak discomfort experienced, the aversive experience will be remembered more positively. The purpose of this study was to evaluate the peak-end rule as applied to high-intensity interval exercise (HIIE). Participants were 30 inactive men (M age = 27.9, SD = 5.2 years). In the first session they performed a graded exercise test on cycle-ergometer to determine their maximal aerobic power (MAP) (M = 233, SD = 35W); and, in the second and third sessions, they performed two HIIE protocols in randomized order: (a) Short trial - 20-minutes of HIIE, composed of 30-second efforts at 100% of MAP interspersed by 30-seconds of passive recovery; and (b) Long trial - 20-minutes of the short trial, plus 10-minutes more of HIIE, decreasing 3% of MAP in each additional bout, resulting in 70% of MAP in the last bout. During exercise, we recorded the participants' rating of perceived exertion (RPE) and affect, using the Feeling Scale (FS). At 30-minutes post-exercise, we again recorded the participants' affect, using the Global Affect Evaluation (GAE) and their session-RPE, and we recorded their enjoyment, using the Physical Activity Enjoyment Scale (PACES). In the last session, the participants chose a favorite protocol to repeat. All sessions were interspersed by at least 72 hours. The 10-minutes extra HIIE in the Long-trial condition resulted decreased heart rate values (M = 157, SD = 13bpm to M = 144, SD = 14bpm; p < 0.001), but psychological responses during and after exercise did not differ, nor did participants' preferred HIIE protocol. As the load drop for the Long-trial was not enough to change the psychological responses during exercise, there was no difference in the retrospective evaluation as the peak-end rule would have suggested.

Purslane supplementation lowers oxidative stress, inflammatory and muscle damage biomarkers after high-intensity intermittent exercise in female runners

Background: The aim of this study was to determine the effect of purslane supplementation on oxidative stress, inflammation and muscle damage biomarkers after completing high-intensity interval exercise (HIIE). Methods: Nine healthy female runners completed a HIIE treadmill protocol comprising 1 min at 100% of the peak treadmill velocity attained in a preliminary exhaustive incremental treadmill test, interspersed by 1 min of passive recovery, until they had run for 2.5 km. Athletes repeated this test following 10 days of supplementation with 1000 mg per day of purslane. Results: At baseline (i.e., absence of purslane supplementation) the HIIE protocol increased 9-HODE (p &lt; 0.001), 13-HODE (p &lt; 0.001), IL-17 (p &lt; 0.001), TNF-α (p &lt; 0.001), and LDH (p &lt; 0.001). After purslane consumption, resting 9-HODE, 13-HODE, IL-17, TNF-α, and LDH were lowered (p &lt; 0.001) and IL-10 was increased (p &lt; 0.001) compared to before purslane supplementation. After purslane consumption and following the HIIE protocol, the responses of these biomarkers were lower compared to baseline (p &lt; 0.001). Conclusion: Ten days of purslane supplementation blunted the perturbation to biomarkers of oxidative stress, inflammation and muscle damage in female runners completing a HIIE protocol.

Acute responses of platelet count and ADP-induced platelet aggregation to different high intensity interval exercise modes.

Platelet activation is associated with abdominal obesity and exercise training is an important modulator of body weight. We investigated the effects of two high intensity interval exercise (HIIE) protocols of different intensity and duration on platelet indices and platelet aggregation in overweight men. Ten overweight men performed 6 intervals of 30s exercise at 110% of peak power output (PPO) interspersed by 3 : 30 min active recovery (1/7 protocol) at 40% of PPO and 6 intervals of 2 min exercise at 85% of PPO interspersed by 2 min active recovery (1/1 protocol) at 30% of PPO in two separate sessions. Platelet indices and platelet aggregation were measured before and immediately after both HIIEs. Platelet indices increased significantly following HIIE (P < 0.05), though, significant differences between the two protocols were only detected for platelet count, which was markedly increased following 1/1 protocol. Platelet aggregation increased significantly (P < 0.05) in response to the two HIIE protocols, with no significant difference being observed between the two protocols (P > 0.05). It is concluded that HIIE leads to transient increases in markers of thrombus formation and that work to rest ratio is an important factor when investigating the changes in thrombocytosis following HIIE.

Positive Affective and Enjoyment Responses to Four High-Intensity Interval Exercise Protocols.

Several variables can be manipulated to compose high-intensity interval exercise (HIIE) protocols, and these different combinations may evoke different psychological responses (affect, enjoyment, mood, and perceived exertion). This study investigated psychological responses during four HIIE protocols. Following anthropometric measurements and two maximal exercise tests, 23 physically inactive adults (11 males [Mage = 25.6, SD = 4.8 years; Mbody mass = 68.5, SD = 12.2 kg; Mheight = 1.72, SD = 0.08 m] and 12 females [Mage = 25.0, SD = 3.5 years; Mbody mass = 57.2, SD = 8.7 kg; Mheight = 1.59, SD = 0.06 m]) performed four different types of HIIE on different days: (a) Long-interval HIIE (HIIEL-10 × 60 seconds:60 seconds), (b) Short-interval HIIE (HIIES-2 blocks of 10 × 30 seconds:30 seconds with 120 seconds between blocks), (c) Repeated Sprint Training (19 × 6 seconds all out:40 seconds), and (d) Sprint Interval Training (4 × 30 seconds all-out efforts: 240 seconds). We used a final session to assess participants' HIIE preference. We recorded participant reports of affect, mood, and perceived exertion throughout protocols, and we recorded enjoyment after exercise session. Perceived exertion significantly increased across all HIIE protocols (p < .001), with higher values in the first quartile during Sprint Interval Training versus HIIEL (p = .033). Affective response presented higher values pre-exercise and at the first quartile compared with all other moments (p < .001). Tension (p < .001) and depression (p = .013) decreased from pre- to post-exercise in all experimental conditions. At pre-exercise, female participants were tenser than males (p = .018), though males presented higher pre-exercise vigor scores than females (p = .023). Vigor increased over time for females (p = .022). Enjoyment did not vary between sexes or protocols. Participants expressed a higher preference for Repeated Sprint Training. HIIE protocols promoted positive psychological responses for physically inactive young adults, and exercise designs may modulate psychological responses.

Do sex-related differences and time of intervals affect the skeletal muscle glycolytic response to high-intensity interval exercise?‏

It may be considered that the duration of intervals of high-intensity interval exercise (HIIE) can affect skeletal muscle biochemical and physiological responses. Also, sex-based differences in muscle biochemistry and physiology play a role in different responses to exercise. The aim of this study was to investigate the effects of sex differences on biochemical parameters involved in muscle glycolysis in response to HIIE protocols with short and long-term intervals. Forty male and female Wistar rats (aged 8 weeks, mean weighting 270 g and 225 g, respectively) were divided into HIIE with short-term interval (HIIESh), HIIE with long-term interval (HIIEL), and control groups. The phosphofructokinase (PFK), glycogen synthase 1 (GYS1), monocarboxylate transporter 4 (MCT4), and lactate dehydrogenase (LDH) levels were evaluated in gastrocnemius muscle after a single bout of exercise. The PFK, GYS1, and MCT4 levels were lower in HIIESh and HIIEL groups compared to the control group. However, there was no significant difference between sexes (P < 0.05). Moreover, the LDH activity was higher in both male and female HIIE rats compared to the control group. It is likely that HIIE with short- and long-term intervals represents similar effects on the glycolytic pathway in both male and female rats.

Multi-ingredient pre-workout supplementation changes energy system contribution and improves performance during high-intensity intermittent exercise in physically active individuals: a double-blind and placebo controlled study

BackgroundNutritional ergogenic aids are commonly used to boost physiological adaptations to exercise and promote greater fitness gains. However, there is a paucity of data about multi-ingredient pre-workout supplementation (MIPS). Therefore, the aim of the present study was to investigate the acute effects of MIPS on the oxidative, glycolytic and ATP-CP energy systems contribution, time spent above 90% V̇O2max (T90% V̇O2max), excess post-exercise oxygen consumption (EPOC) magnitude, number of efforts and time to exhaustion during a high-intensity interval exercise (HIIE) session.MethodsTwelve physically-active and healthy men completed the HIIE sessions that involved running bouts of 15 s on the treadmill at 120% of the maximum aerobic speed (MAS), interspersed with 15 s of passive recovery. Blood lactate was collected at immediately post, 3, 5, and 7 min post exercise. The contribution of ATP-CP, glycolytic and oxidative systems was analyzed at rest, during the HIIE sessions and for 20 min post. Performance variables (time to exhaustion, number of efforts) and oxygen consumption were also analyzed.ResultsMIPS significantly increased the number of efforts performed (MIPS: 41 ± 10 vs Placebo: 36 ± 12, p = 0.0220) and time to exhaustion (MIPS: 20.1 ± 6 min vs Placebo: 17 ± 5 min, p = 0.0226). There was no difference between supplements for both T90% V̇O2max (p = 0.9705) and EPOC (p = 0.4930). Consuming MIPS significantly increased the absolute oxidative energy system contribution by 23.8% (p = 0.0163) and the absolute ATP-CP contribution by 28.4% (p = 0.0055) compared to placebo. There was only a non-significant tendency for a higher glycolytic system contribution after MIPS ingestion (p = 0.0683).ConclusionAcute MIPS ingestion appears effective at increasing both aerobic and anaerobic alactic energy contribution and time to exhaustion during a HIIE protocol.

Two protocols of aerobic exercise modulate the counter-regulatory axis of the renin-angiotensin system

AimsThe renin-angiotensin system (RAS) is a dual system with two opposite arms: i) the classical one formed by the angiotensin converting enzyme (ACE), angiotensin (Ang) II and angiotensin type 1 (AT1) receptors; ii) the counter-regulatory arm consisting of ACE2, Ang-(1–7) and Mas receptor. Physical exercise can modulate this system, however, only animal studies have compared the effects of different intensity protocols on the RAS. No data with humans were provided. Therefore, we investigated the acute effect of two protocols of isowork aerobic exercise [High-Intensity Interval Exercise (HIIE) and Moderate-Intensity Continuous Exercise (MICE)] in plasma and urinary levels of RAS components in physically active men. Main methodsThe HIIE protocol included a 5-minute warm-up cycling at 60–70% of heart rate peak (HRp) intensity followed by 10 sets of 30 s above 90% with 1 min of recovery and 3 min of cool down. The MICE protocol was performed at a constant power corresponding to 60–70% of HRp and finalized at the same total work of HIIE. Blood and urine samples were collected before and after the protocols. Plasma and urinary levels of ACE, ACE2, Ang-(1–7) and Ang II were analyzed by enzyme-linked immunoassay. Key findingsWhile the HIIE protocol significantly increased urinary levels of ACE and plasma levels of ACE2, the MICE protocol elevated urinary concentrations of ACE2 and of Ang-(1–7). A greater increase of urine concentrations of Ang-(1–7) occurred in the MICE if compared with the HIIE protocol. SignificanceAerobic physical exercise acutely increases the activity of the counter-regulatory RAS axis, mostly the MICE protocol.